Verbal initiation, selection, strategy, and inhibition in stroke: A brief executive function screening tool

Executive dysfunction is prevalent in early stroke and can predict long-term outcomes. Impairments can be subtle and undetected in cognitive stroke screens. To better assess executive functions, this study introduced a novel sentence completion test, which assesses multiple executive processes in <5 minutes (Brief Executive Language Screen - Sentence Completion; BELS-SC). The aim was to determine construct, convergent and divergent validity, sensitivity and specificity of the BELS-SC, and to explore differences between left and right hemisphere stroke patients (LHS and RHS, respectively) on the BELS-SC and standard executive function tests.

Eighty-eight acute/early sub-acute stroke patients and 116 age-matched healthy controls were included.

Principal Component Analysis (PCA) suggested four to five factors of the BELS-SC: Initiation, Selection, Inhibition (with strategy loading on Inhibition), Inhibition Response Time, and Semantic Retrieval Response Time. The BELS-SC had good sensitivity (.84) but poorer specificity (.66) differentiating controls and stroke, and good sensitivity (.83) and specificity (.80) differentiating executive function impaired versus executive function intact groups. BELS-SC Initiation and Inhibition subtests demonstrated convergent and divergent validity with corresponding Hayling subtests. LHS and RHS showed impairment across initiation, selection, inhibition and strategy; however, greatest deficits were shown by RHS on Inhibition items requiring suppression of one dominant response. More patients were impaired on BELS-SC than other executive function tests.

The BELS-SC demonstrated convergent, divergent, and construct validity, good sensitivity and specificity, taps multiple executive processes, and provides insight into strategy. Use in early stroke may aid in targeted and timely cognitive rehabilitation.